Fatal sleeping sickness can spread through skin

December 19, 2016

London, Dec 19: Skin plays a significant role in harbouring and transmitting a parasite that causes African sleeping sickness - a condition which is often fatal if left untreated, a new study has found.flly

The study by researchers from the University of Glasgow in Scotland and the Institut Pasteur in France, may have a major impact on the way the disease is diagnosed, treated and potentially eradicated.

The disease, which kills thousands in Sub-Saharan African every year, is primarily transmitted to humans via the bite of an infected tsetse fly as it takes a blood meal, with diagnosis then confirmed through the presence of parasites in the blood.

The new study definitively shows that substantial quantities of trypanosomes that cause the disease exist within the skin and can be transmitted back to the tsetse fly vector, even in the absence of detectable signs of infection in the animal or detectable parasites in the blood.

The researchers were also able to observe the presence of parasites in human skin biopsies from individuals who displayed no symptoms.

The study's findings suggest skin-dwelling parasites may be sufficiently abundant in the skin to be ingested, transmitted and so able to spread the disease further.

"Our results have important implications with regard to the eradication of sleeping sickness," said Annette MacLeod from University of Glasgow.

"Firstly, our findings indicate that current diagnostic methods, which rely on observing parasites in the blood, should be re-evaluated and should include examining the skin for parasites," said MacLeod.

"In terms of treatment, it may also be necessary to develop novel therapeutics capable of targeting sources of infection outside the blood circulation and in the reservoirs underneath the skin," she said.

The findings also suggest the need for a re-evaluation of disease control policies.

The current policy of the World Health Organisation (WHO) is to avoid treating people who do not show any symptoms of sleeping sickness, unless parasites are detected in their blood, due to the long duration and high toxicity of the treatment, MacLeod said.

"This policy should be reconsidered in light of our compelling evidence that these patients represent a carrier population," she said.

"This is because their lack of treatment may help maintain disease outbreaks and explain previously thwarted efforts to eliminate this major pathogen," she added.

The study appears in the journal eLife.

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Agencies
July 2,2020

The American pharmaceutical giant Pfizer Inc. and the European biotechnology company BioNTech SE have conducted an experimental trial of a COVID-19 vaccine candidate and found it to be safe, well-tolerated, and capable of generating antibodies in the patients.

The study, which is yet to be peer-reviewed, describes the preliminary clinical data for the candidate vaccine -- nucleoside-modified messenger RNA (modRNA), BNT162b1.

It said the amount of antibodies produced in participants after they received two shots of the vaccine candidate was greater than that reported in patients receiving convalescent plasma from recovered COVID-19 patients.

"I was glad to see Pfizer put up their phase 1 trial data today. Virus neutralizing antibody titers achieved after two doses are greater than convalescent antibody titers," tweeted Peter Hotez, a vaccine scientist from Baylor College of Medicine in the US, who was unrelated to the study.

Researchers, including those from New York University in the US, who were involved in the study, said the candidate vaccine enables human cells to produce an optimised version of the receptor binding domain (RBD) antigen -- a part of the spike (S) protein of SARS-CoV-2 which it uses to gain entry into human cells.

"Robust immunogenicity was observed after vaccination with BNT162b1," the scientists noted in the study.

They said the program is evaluating at least four experimental vaccines, each of which represents a unique combination of mRNA format and target component of the novel coronavirus, SARS-CoV-2.

Based on the study's findings, they said BNT162b1 could be administered in a quantity that was well tolerated, potentially generating a dose dependent production of immune system molecules in the patients.

The research noted that patients treated with the vaccine candidate produced nearly 1.8 to 2.8 fold greater levels of RBD-binding antibodies that could neutralise SARS-CoV-2.

"We are encouraged by the clinical data of BNT162b1, one of four mRNA constructs we are evaluating clinically, and for which we have positive, preliminary, topline findings," said Kathrin U. Jansen, study co-author and Senior Vice President and Head of Vaccine Research & Development, Pfizer.

"We look forward to publishing our clinical data in a peer-reviewed journal as quickly as possible," Jansen said.

According to Ugur Sahin, CEO and Co-founder of BioNTech, and another co-author of the study, the preliminary data are encouraging as they provide an initial signal that BNT162b1 is able to produce neutralising antibody responses in humans.

He said the immune response observed in the patients treated with the experimental vaccine are at, or above, the levels observed from convalescent sera, adding that it does so at "relatively low dose levels."

"We look forward to providing further data updates on BNT162b1," Sahin said.

According to a statement from Pfizer, the initial part of the study included 45 healthy adults 18 to 55 years of age.

It said the priliminary data for BNT162b1 was evaluated in 24 subjects who received two injections of 10 microgrammes ( g) and 30 g -- 12 subjects who received a single injection of 100 g, and 9 subjects who received two doses of a dummy vaccine.

The study noted that participants received two doses, 21 days apart, of placebo, 10 g or 30 g of BNT162b1, or received a single dose of 100 g of the vaccine candidate.

According to the scientists, the highest neutralising concentrations of antibodies were observed seven days after the second dose of 10 g, or 30 g on day 28 after vaccination.

They said the neutralising concentrations were 1.8- and 2.8-times that observed in a panel of 38 blood samples from people who had contracted the virus.

In all 24 subjects who received two vaccinations at 10 g and 30 g dose levels, elevation of RBD-binding antibody concentrations was observed after the second injection, the study noted.

It said these concentrations are 8- and 46.3-times the concentration seen in a panel of 38 blood samples from those infected with the novel coronavirus.

At the 10 g or 30 g dose levels, the scientists said adverse reactions, including low grade fever, were more common after the second dose than the first dose.

According to Pfizer, local reactions and systemic events after injection with 10 g and 30 g of BNT162b1 were "dose-dependent, generally mild to moderate, and transient."

It said the most commonly reported local reaction was injection site pain, which was mild to moderate, except in one of 12 subjects who received a 100 g dose, which was severe.

The study noted that there was no serious adverse events reported by the patients.

Citing the limitations of the research, the scientists said the immunity generated in the participants in the form of the T cells and B cells of their immune system, and the level of immunity needed to protect one from COVID-19 are unknown.

With these preliminary data, along with additional data being generated, Pfizer noted in the statement that the two companies will determine a dose level, and select among multiple vaccine candidates to seek to progress to a large, global safety and efficacy trial, which may involve up to 30,000 healthy participants if regulatory approval to proceed is received.

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Agencies
May 17,2020

Geneva, May 17: Spraying disinfectant on the streets, as practised in some countries, does not eliminate the new coronavirus and even poses a health risk, the World Health Organization (WHO) warned on Saturday.

In a document on cleaning and disinfecting surfaces as part of the response to the virus, the WHO says spraying can be ineffective. "Spraying or fumigation of outdoor spaces, such as streets or marketplaces, is... not recommended to kill the Covid-19 virus or other pathogens because disinfectant is inactivated by dirt and debris," explains the WHO.

"Even in the absence of organic matter, chemical spraying is unlikely to adequately cover all surfaces for the duration of the required contact time needed to inactivate pathogens." The WHO said that streets and pavements are not considered as "reservoirs of infection" of Covid-19, adding that spraying disinfectants, even outside, can be "dangerous for human health".

The document also stresses that spraying individuals with disinfectants is "not recommended under any circumstances".

"This could be physically and psychologically harmful and would not reduce an infected person's ability to spread the virus through droplets or contact," said the document.

Spraying chlorine or other toxic chemicals on people can cause eye and skin irritation, bronchospasm and gastrointestinal effects, it adds.

The organisation is also warning against the systematic spraying and fumigating of disinfectants on to surfaces in indoor spaces, citing a study that has shown it to be ineffective outside direct spraying areas.

"If disinfectants are to be applied, this should be done with a cloth or wipe that has been soaked in disinfectant," it says.

The SARS-CoV-2 virus, the cause of the pandemic that has killed more than 300,000 people worldwide since its appearance in late December in China, can attach itself to surfaces and objects.

However, no precise information is currently available for the period during which the viruses remain infectious on the various surfaces.

Studies have shown that the virus can stay on several types of surfaces for several days. However, these maximum durations are only theoretical because they are recorded under laboratory conditions and should be "interpreted with caution" in the real-world environment.

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Agencies
May 23,2020

Food with high water content is highly prescribed by doctors to stay hydrated during the summers, a season that summons a wave of soaring temperatures, higher than 40-degrees.

A much-loved fruit in India, apples are hydrating heros' in such a situation. A heatwave can affect human health in a varied manner and to maintain ideal body temperature in this soaring summer, one must remain adequately hydrated, be protected from the sun and maintain hygiene.

Working professionals and people who must step out in summers, are prone to the heatwave impact. Pediatric experts and doctors agree on the benefits of drinking water and eating fruits, especially, apples. 'An apple a day, keeps the doctor away' is true as they are rich in a number of vitamins with great anti-inflammatory benefits and many other essential minerals. Washington Apple Commission spells how apples can prove to be a summer-friendly fruit.

People often don't realise the danger of exposing themselves to extreme heat. Older adults, young children, and people with chronic illnesses are most at greater risk for serious problems. The nutrition benefits of apples may help not only in avoiding such illnesses but may also protect against many such conditions.

As popular as apples are as a fruit, they are enriched in antioxidants, dietary fibers, vitamins and a range of other nutrients that are greatly beneficial in maintaining good health. The fruit is rich in soluble fibers which may help prevent several health conditions and may lower the risk of major diseases such as heat strokes, diabetes and cancer.

The soluble fiber also promotes weight loss and improves gut health. The prebiotic effects of apples help feed the good bacteria in the gut, thus, improving digestion.

Apples are made of 85 percent water and contain vitamins, fibres and antioxidants. A high fibre content is a particularly beneficial property of apples, as improper digestion is a major health concern in the tropical climatic region. Apples are also enriched in antioxidants that help protect the lungs from oxidative damage and help oxygen flow through the blood.

Apple-based recipes

Make interesting snacks, dessert, beverages and savoury meals with this miraculous fruit during summers.

Salted apple caramel galette

Caramel apples get a grown-up makeover with this Salted Caramel Apple Galette. Warm, gooey, and delicious, this pastry is loaded with apples and homemade caramel. It's a sophisticated take on a childhood favorite and since it's easier to make than pie, it's perfect for summer get-togethers.

Caramel apple pie ice-cream sandwiches

Nothing is better at a cookout on a warm day than a cold, refreshing ice cream sandwich. In Caramel Apple Pie Ice Cream Sandwiches, the comforting flavor of apple pie is recreated in a creamy frozen banana-based ice cream studded with apple and date pieces. Then that scoop of ice cream is sandwiched between two pieces of no-bake cinnamon oat cookie dough.

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